Temperature should be moved from attributes to PMs

[bcjohnso99]

Temperature (of equipment and laser) should be moved from attributes to PMs

[nigel-r-davis]

Agreed. There may be several other attributes that should be moved, we should review all attributes briefly.

PMs are best propagated via streaming. A snapshot stream can be used of an instantaneous reading of the value (which a read of the property would have given). The snapshot stream is referenced elsewhere and we can discuss on a call.